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J J. ABELL & C. B. GIPFORD. PRIMARY ELEGTRIO CLOCK.

No, 360,078.- Patented Mar. 29, 1887.

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J. J. ABELL & 0. B. GIFFORD. PRIMARY ELEGTRIG CLOCK.

No. 360,078. PatentedMar. 29, 1887.

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UNITED STATES PATENT- OFFICE.

JOHN JAMES ABELL AND CLARENCE BED GIFFORD, OF COLESBURG, KY.

PRIMARY ELECTRIC CLOCK.

SPECIFIC ION forming part of Letters Patent No.360,078, dated March 29,1887.

Application filed November 27, 1836. Serial No. 220,074. (X modcll) .T 0all whom it may concern.-

Be it known that we, JOHN JAMES ABELL and CLARENCE BEN GIFFORD, citizensof the United States, residing 'at Colesburg, in the county ofHardin-and State of Kentucky, have invented new and useful Improvementsin Electric Clocks and Electric-Clock Systems, of which the following isa specification.

Our invention relates to improvements in electric clocks andelectric-clock systems; and it consists in the circuit including thesecondary cloeks'and the primary clocks having the devices to close thesaid circuit at suitable regular intervals of time;

It further consists in the combination, in a clock, of theescapement-wheel, the anchor, and the spring to move theescapement-wheel during the interval when it is disengaged by the pointsof the anchor.

Our invention further consists in the peeuliar construction andcombination of devices, that will be more fully set forth hereinafter,and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is I a diagram of anelectric-clock system embodymounted on the arbor a, and is also providedwith thirty teeth. The front end of the arbor a extends through a hollowspindle, e, that projects from the front side of the frame in which theclock mechanism is mounted. A coiled hair-spring, f, has its inner endat tached to the arbor a,and its outer end attached to theratchet-wheel, and thereby, when the ratchet-wheel is rotated in thedirection indicated by the arrow in Fig. 3 and independently of thearbor a, the spring will be coiled or wound. A gravity-pawl, g, ispivoted to a fixed point and engages the ratchet-wheel, so as to preventretrograde rotation thereof.

Near one end of the arbor a is a pinion, 71, which meshes with agear-wheel, i, on a shaft, 70, the said shaft being connected to thehollow sleeves that carry the minute and hour hands by suitablegear-wheels, which need not be more particularly described herein, asthey are of the usual construction and arrangement.

Attached to the clock-frame is an electro magnet, Z, and journaled inthe said frame is a rock-shaft, m, carrying an armature, a, that isopposed to the poles of the electro-magnet. The vibration of thearmature is limited by adjustable stops a and a". Pivoted to thearmature is a gravity-pawl, 0, that also engages the ratchet-wheel. Ananchor, 19, is attached to the armature and is vibrated thereby, thesaid anchor having the points 1) and p to engage the teeth of theescapement-wheel.

A retracting-spring, 1, is adapted to draw the armature from the magnetwhen the latter is demagnetized, and a tension device, 8, is provided toregulate the strength of the said spring.

The ratchet-wheel d has on one side a projceting contact-point, t, thatis adapted to contact with a point, a, once at each rotation of the saidratchet-wheel. The point a is carried by the anchor and movestherewitl1,and is within the path of the point t whelrthe arma ture isattracted by the electro-magnet. The points i and to form the terminalsof the circuit 1;, in which is included the electromagnet w of one ormore secondary Clocks, 13. A. battery, x, or other suitable source ofelectricity, is also included in the circuit '0.

The secondary clocks are similar in construction to the primary clockshereinbefore described, with the exception that the minutehands thereofare so geared to the armatures of their electro-magnets that the saidhands will be moved 011 their dials through the space, indicating aminute every time that their armatures are attracted.

It will be of course understood that the secondary clocks are notprovided with secondhands, and hence do not mark intervals of time lessthan one minute in duration.

C represents a pendulum such as described in Letters Patent of theUnited States No. 351,239, granted to us October 19, 1886. This pendulumswings once every second, and is adapted at each vibration in onedirection to close the circuit 2, which includes the battery a and the,electro-magnet of the primary clock.

The operation of our invention is as follows: When the circuit a isopen, at each alternate movement of the pendulum the spring 7 retractsthe armature,thereby moving the anchor against the stop n and causingthe point p to engage a tooth of the escapement -wheel. When thependulum swings in the contrary direction during the ensuing second oftime, the circuit 2 is closed, the cores of the electromagnet Z aremagnetized, and the armature it attracted thereby, thus causing thepoint p to disengage the tooth of the escapement-wheel with which it isin contact, thereby releasing the escapement-wheel, and causing thehairspringf, in its natural tendency to uncoil, to move theescapement-wheel in the direction indicated by the arrow in Fig. 3 adistance corresponding to one-half a tooth, when it is engaged by thepoint p" of the anchor. The pawl g prevents the ratchetwheel fromretrograding while the pawl 0 is slipping back on the same when thearmature is attracted. At the ensuing stroke of the pendulum, when thecircuit 2 is broken, the armature is retracted by the spring r, andcauses the pawl o to turn the ratchet-wheel d loosely on the arbor a inthe direction opposite that indicated by the arrow in Fig. 3 adistancecorresponding to half a tooth, while the escapement-wheel is held fast,thus winding the hair-spring sufficiently to compensate for the slightprevious uncoiling action thereof, hereinbefore described, andconsequently preserving the tension of the spring f, so that itsstrength will be at all times sufficient to propel the train. At eachstroke of the pendulum the secondhand of the primary clock is moved overthe dial a corresponding distance, and as the gears which actuate thehour and minute hands are connected with the second-hand arbor a, asshown and hereinbefore stated, it follows that the said hour and minutehands will be correspondinglymoved on the dial. At each completerevolution of the ratchet and escapem ent wheels of the primary clock,which occurs every minute, the point t, which is carried by theratchet-wheel, comes in contact with the point a and closes the circuit12, thereby cansing the electro magnets of the secondary clocks to bemagnetized and attract their armatures, and thus move their handsthrough a space on the dials corresponding to a minute of time. Thiscauses the primary and secondary clock mechanisms to move synchronously.

The primary clock is provided with the second-hand moved synchronouslywith the pendnlum, in order that any inaccuracies may be noted and thependulum regulated by the means described in our before-mentionedLetters Patent, so as to cause the system of clocks to indicateprecisely the correct time.

The loose ratchet-wheel on the arbor a and the hair-spring connectingthe said ratchetwheel to the said shaft cause the escapementwheel to bepositively impelled at each movement of the anchor, so that it will beimpossible for the points or teeth of the anchor to fail to move theeseapementwheel, and thus impair the accuracy of the clock.

\Ve do not desire to limit ourselves to the precise constructionhereinbefore described, as it is evident that modifications may be madetherein without departing from the spirit of our invention.

Having thus described our invention, we claim- 1. In the escapementmechanism of a clock, the combination of the escapement-wheel, theanchor, the ratchet-wheel free to move independently of theescapement-wheel, the pawl movable with the anchor and engaging theratchet-wheel, the detent to prevent retrograde movement thereof, andthe spring connecting the ratchet-wheel and the escapement-wheel to movethe latter during the instant that it is disengaged by the anchor,substantially as described.

2. In the escapement mechanism of a clock, the combination of theescapement-wheel, the anchor, the rotating wheel (Z, independent of theescapement-wheel, and the spring connecting the said wheel d and theescapement-wheel to move the latter during the instant it is disengagedby the anchor, substantially as described.

3. In a primary electric clock, the combination of the anchor, theescapement-wheel movable by the anchor, and the spring 1', andelectro-magnet to operate the latter, the ratchet wheel (1, independentof the escapement-wheel and having the contaet-point't, forming theterminal of the electric circuit, the detent to prevent retrograderotation of the ratchet-wheel, the pawl carried by the anchor andengaging the ratchet-wheel, the spring connecting the ratchet-wheel andthe escapement-wheel, for the purpose set forth, and the vibrating pointit, carried by the anchor and forming the other terminal of the circuit,and adapted to come in contact with the point i at regular intervals oftime, for the purpose set forth, substantially as described.

In testimony that we claim the foregoing as our own we have heretoaffixed our signatures in presence of two witnesses.

JOHN JAMES ABELL. CLARENCE BEN GIFFORI). Witnesses:

W. T. SAMUELS, JOHN B. QUioeINs.

